Method and apparatus for small data transmission

ABSTRACT

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method and apparatus for small data transmission are provided.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. §119(a) of a Korean patent application number 10-2020-0087541, filed onJul. 15, 2020, in the Korean Intellectual Property Office, thedisclosure of which is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates to a wireless communication system. Moreparticularly, the disclosure relates to an apparatus, a method and asystem for small data transmission in wireless communication system.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of fourth generation (4G) communication systems, efforts havebeen made to develop an improved fifth generation (5G) or pre-5Gcommunication system. The 5G or pre-5G communication system is alsocalled a ‘Beyond 4G Network’ or a ‘Post long term evolution (LTE)System’. The 5G communication system is considered to be implemented inhigher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplishhigher data rates. To decrease propagation loss of the radio waves andincrease the transmission distance, the beamforming, massivemultiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO),array antenna, an analog beam forming, large scale antenna techniquesare discussed in 5G communication systems. In addition, in 5Gcommunication systems, development for system network improvement isunder way based on advanced small cells, cloud Radio Access Networks(RANs), ultra-dense networks, device-to-device (D2D) communication,wireless backhaul, moving network, cooperative communication,Coordinated Multi-Points (CoMP), reception-end interference cancellationand the like. In the 5G system, Hybrid frequency shift keying (FSK) andquadrature amplitude modulation (QAM) (FQAM) and sliding windowsuperposition coding (SWSC) as an advanced coding modulation (ACM), andfilter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA),and sparse code multiple access (SCMA) as an advanced access technologyhave been developed.

The Internet, which is a human centered connectivity network wherehumans generate and consume information, is now evolving to the Internetof Things (IoT) where distributed entities exchange and processinformation without human intervention. The Internet of Everything(IoE), which is a combination of the IoT technology and the Big Dataprocessing technology through connection with a cloud server, hasemerged. As technology elements, such as “sensing technology”,“wired/wireless communication and network infrastructure”, “serviceinterface technology”, and “Security technology” have been demanded forIoT implementation, a sensor network, a Machine-to-Machine (M2M)communication, Machine Type Communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. IoT maybe applied to a variety of fields including smart home, smart building,smart city, smart car or connected cars, smart grid, health care, smartappliances and advanced medical services through convergence andcombination between existing Information Technology (IT) and variousindustrial applications.

In line with this, various attempts have been made to apply 5Gcommunication systems to IoT networks. For example, technologies such asa sensor network, Machine Type Communication (MTC), andMachine-to-Machine (M2M) communication may be implemented bybeamforming, MIMO, and array antennas. Application of a cloud RadioAccess Network (RAN) as the above-described Big Data processingtechnology may also be considered to be as an example of convergencebetween the 5G technology and the IoT technology.

Meanwhile, there have been various studies on small data transmission(SD) in 5G communication system recently.

The above information is presented as background information only toassist with an understanding of the disclosure. No determination hasbeen made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the disclosure is to providea communication method and system for converging a fifth generation (5G)communication system for supporting higher data rates beyond a fourthgeneration (4G).

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

In accordance with an aspect of the disclosure, a method performed by aterminal is provided. The method includes receiving, from a basestation, a radio resource control (RRC) release message including atleast one configured grant uplink resource for a small data transmission(SDT), identifying an uplink carrier among a normal uplink (NUL) or asupplementary uplink (SUL), based on an SDT procedure initiated whilethe terminal is in an RRC inactive state, identifying a synchronizationsignal block (SSB) among SSBs associated with configured grant uplinkresources for the SDT procedure on the identified uplink carrier, andtransmitting, to the base station, uplink data in an uplink grantcorresponding to the identified SSB.

In accordance with another aspect of the disclosure, a method performedby a base station is provided. The method includes transmitting, to aterminal, a radio resource control (RRC) release message including atleast one configured grant uplink resource for a small data transmission(SDT), and receiving, from the terminal, uplink data in an uplink grantcorresponding to a synchronization signal block (SSB), based on an SDTprocedure initiated while the terminal is in an RRC inactive state,wherein the SSB is one among a plurality of SSBs associated withconfigured grant uplink resources for the SDT procedure on an uplinkcarrier, and wherein the uplink carrier is one among a normal uplink(NUL) or a supplementary uplink (SUL).

In accordance with another aspect of the disclosure, a terminal isprovided. The terminal includes a transceiver, and at least oneprocessor configured to receive, from a base station via thetransceiver, a radio resource control (RRC) release message including atleast one configured grant uplink resource for a small data transmission(SDT), identify an uplink carrier among a normal uplink (NUL) or asupplementary uplink (SUL), based on an SDT procedure initiated whilethe terminal is in an RRC inactive state, identify a synchronizationsignal block (SSB) among SSBs associated with configured grant uplinkresources for the SDT procedure on the identified uplink carrier, andtransmit, to the base station via the transceiver, uplink data in anuplink grant corresponding to the identified SSB.

In accordance with another aspect of the disclosure, a base station isprovided. The base station includes a transceiver, and at least oneprocessor configured to transmit, to a terminal via the transceiver, aradio resource control (RRC) release message including at least oneconfigured grant uplink resource for a small data transmission (SDT),and receive, from the terminal via the transceiver, uplink data in anuplink grant corresponding to a synchronization signal block (SSB),based on an SDT procedure initiated while the terminal is in an RRCinactive state, wherein the SSB is one among a plurality of SSBsassociated with configured grant uplink resources for the SDT procedureon an uplink carrier, and wherein the uplink carrier is one among anormal uplink (NUL) or a supplementary uplink (SUL).

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates an example of small data transmission usingpre-configured uplink grant according to an embodiment of thedisclosure;

FIG. 2 illustrates an example of association between synchronizationsignal block and uplink grant according to an embodiment of thedisclosure;

FIG. 3 illustrates another example of association betweensynchronization signal block and uplink grant according to an embodimentof the disclosure;

FIG. 4 illustrates a flow chart for small data transmission usingpreconfigured uplink resource according to an embodiment of thedisclosure;

FIG. 5 illustrates a flow chart for small data transmission usingpreconfigured uplink resource according to an embodiment of thedisclosure;

FIG. 6 illustrates a flow chart for generating medium access control(MAC) protocol data unit (PDU) for small data according to an embodimentof the disclosure;

FIG. 7 illustrates a flow chart for generating MAC PDU for small datatransmission according to an embodiment of the disclosure;

FIG. 8 is a block diagram of a terminal according to an embodiment ofthe disclosure; and

FIG. 9 is a block diagram of a base station according to an embodimentof the disclosure.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding, but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thedisclosure. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but are merely used by theinventor to enable a clear and consistent understanding of thedisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of thedisclosure is provided for illustration purposes only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

By the term “substantially” it is meant that the recited characteristic,parameter, or value need not be achieved exactly, but that deviations orvariations, including for example, tolerances, measurement error,measurement accuracy limitations and other factors known to those ofskill in the art, may occur in amounts that do not preclude the effectthe characteristic was intended to provide.

It is known to those skilled in the art that blocks of a flowchart (orsequence diagram) and a combination of flowcharts may be represented andexecuted by computer program instructions. These computer programinstructions may be loaded on a processor of a general purpose computer,special purpose computer, or programmable data processing equipment.When the loaded program instructions are executed by the processor, theycreate a means for carrying out functions described in the flowchart.Because the computer program instructions may be stored in a computerreadable memory that is usable in a specialized computer or aprogrammable data processing equipment, it is also possible to createarticles of manufacture that carry out functions described in theflowchart. Because the computer program instructions may be loaded on acomputer or a programmable data processing equipment, when executed asprocesses, they may carry out operations of functions described in theflowchart.

A block of a flowchart may correspond to a module, a segment, or a codecontaining one or more executable instructions implementing one or morelogical functions, or may correspond to a part thereof. In some cases,functions described by blocks may be executed in an order different fromthe listed order. For example, two blocks listed in sequence may beexecuted at the same time or executed in reverse order.

In this description, the words “unit”, “module” or the like may refer toa software component or hardware component, such as, for example, afield-programmable gate array (FPGA) or an application-specificintegrated circuit (ASIC) capable of carrying out a function or anoperation. However, a “unit”, or the like, is not limited to hardware orsoftware. A unit, or the like, may be configured so as to reside in anaddressable storage medium or to drive one or more processors. Units, orthe like, may refer to software components, object-oriented softwarecomponents, class components, task components, processes, functions,attributes, procedures, subroutines, program code segments, drivers,firmware, microcode, circuits, data, databases, data structures, tables,arrays or variables. A function provided by a component and unit may bea combination of smaller components and units, and may be combined withothers to compose larger components and units. Components and units maybe configured to drive a device or one or more processors in a securemultimedia card.

Prior to the detailed description, terms or definitions necessary tounderstand the disclosure are described. However, these terms should beconstrued in a non-limiting way.

The base station (BS) is an entity communicating with a user equipment(UE) and may be referred to as BS, base transceiver station (BTS), nodeB (NB), evolved NB (eNB), access point (AP), 5G NB (5GNB), or nextgeneration node B (gNB).

The UE is an entity communicating with a BS and may be referred to asUE, device, mobile station (MS), mobile equipment (ME), or terminal.

In the recent years several broadband wireless technologies have beendeveloped to meet the growing number of broadband subscribers and toprovide more and better applications and services. The second generationwireless communication system has been developed to provide voiceservices while ensuring the mobility of users. Third generation wirelesscommunication system supports not only the voice service but also dataservice. In recent years, the fourth wireless communication system hasbeen developed to provide high-speed data service. However, currently,the fourth generation wireless communication system suffers from lack ofresources to meet the growing demand for high speed data services. So afifth generation wireless communication system is being developed tomeet the growing demand for high speed data services, supportultra-reliability and low latency applications.

The fifth generation wireless communication system will be implementednot only in lower frequency bands but also in higher frequency (mmWave)bands, e.g., 10 GHz to 100 GHz bands, so as to accomplish higher datarates. To mitigate propagation loss of the radio waves and increase thetransmission distance, beamforming, massive Multiple-InputMultiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, and large scale antenna techniques are beingconsidered in the design of fifth generation wireless communicationsystem. In addition, the fifth generation wireless communication systemis expected to address different use cases having quite differentrequirements in terms of data rate, latency, reliability, mobility etc.However, it is expected that the design of the air-interface of thefifth generation wireless communication system would be flexible enoughto serve the UEs having quite different capabilities depending on theuse case and market segment the UE cater service to the end customer.Few example use cases the fifth generation wireless communication systemwireless system is expected to address is enhanced Mobile Broadband(eMBB), massive Machine Type Communication (m-MTC), ultra-reliable lowlatency communication (URLL) etc. The eMBB requirements like tens ofGbps data rate, low latency, high mobility so on and so forth addressthe market segment representing the conventional wireless broadbandsubscribers needing internet connectivity everywhere, all the time andon the go. The m-MTC requirements like very high connection density,infrequent data transmission, very long battery life, low mobilityaddress so on and so forth address the market segment representing theInternet of Things (IoT)/Internet of Everything (IoE) envisioningconnectivity of billions of devices. The URLL requirements like very lowlatency, very high reliability and variable mobility so on and so forthaddress the market segment representing the Industrial automationapplication, vehicle-to-vehicle/vehicle-to-infrastructure communicationforeseen as one of the enabler for autonomous cars.

In the fifth generation wireless communication system operating inhigher frequency (mmWave) bands, UE and gNB communicates with each otherusing Beamforming. Beamforming techniques are used to mitigate thepropagation path losses and to increase the propagation distance forcommunication at higher frequency band. Beamforming enhances thetransmission and reception performance using a high-gain antenna.Beamforming can be classified into Transmission (TX) beamformingperformed in a transmitting end and reception (RX) beamforming performedin a receiving end. In general, the TX beamforming increases directivityby allowing an area in which propagation reaches to be densely locatedin a specific direction by using a plurality of antennas.

In this situation, aggregation of the plurality of antennas can bereferred to as an antenna array, and each antenna included in the arraycan be referred to as an array element. The antenna array can beconfigured in various forms such as a linear array, a planar array, etc.The use of the TX beamforming results in the increase in the directivityof a signal, thereby increasing a propagation distance. Further, sincethe signal is almost not transmitted in a direction other than adirectivity direction, a signal interference acting on another receivingend is significantly decreased. The receiving end can performbeamforming on a RX signal by using a RX antenna array. The RXbeamforming increases the RX signal strength transmitted in a specificdirection by allowing propagation to be concentrated in a specificdirection, and excludes a signal transmitted in a direction other thanthe specific direction from the RX signal, thereby providing an effectof blocking an interference signal.

By using beamforming technique, a transmitter can make plurality oftransmit beam patterns of different directions. Each of these transmitbeam patterns can be also referred as TX beam. Wireless communicationsystem operating at high frequency uses plurality of narrow TX beams totransmit signals in the cell as each narrow TX beam provides coverage toa part of cell. The narrower the TX beam, higher is the antenna gain andhence the larger the propagation distance of signal transmitted usingbeamforming A receiver can also make plurality of RX beam patterns ofdifferent directions. Each of these receive patterns can be alsoreferred as RX beam.

The fifth generation wireless communication system (also referred asnext generation radio or NR), supports standalone mode of operation aswell dual connectivity (DC). In DC a multiple Rx/Tx UE may be configuredto utilize resources provided by two different nodes (or NBs) connectedvia non-ideal backhaul. One node acts as the Master Node (MN) and theother as the Secondary Node (SN). The MN and SN are connected via anetwork interface and at least the MN is connected to the core network.NR also supports Multi-RAT Dual Connectivity (MR-DC) operation whereby aUE in radio resource control connected (RRC_CONNECTED) is configured toutilize radio resources provided by two distinct schedulers, located intwo different nodes connected via a non-ideal backhaul and providingeither E-UTRA (Evolved Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access) (i.e., if the node is an ng-eNB) or NR access(i.e., if the node is a gNB). In NR for a UE in RRC_CONNECTED notconfigured with carrier aggregation (CA)/DC there is only one servingcell comprising of the primary cell. For a UE in RRC_CONNECTEDconfigured with CA/DC the term ‘serving cells’ is used to denote the setof cells comprising of the Special Cell(s) and all secondary cells. InNR the term Master Cell Group (MCG) refers to a group of serving cellsassociated with the Master Node, comprising the Primary Cell (PCell) andoptionally one or more Secondary Cells (SCells). In NR the termSecondary Cell Group (SCG) refers to a group of serving cells associatedwith the Secondary Node, comprising the Primary SCG Cell (PSCell) andoptionally one or more SCells. In NR PCell refers to a serving cell inMCG, operating on the primary frequency, in which the UE either performsthe initial connection establishment procedure or initiates theconnection re-establishment procedure. In NR for a UE configured withCA, Scell is a cell providing additional radio resources on top ofSpecial Cell. PSCell refers to a serving cell in SCG in which the UEperforms random access when performing the Reconfiguration with Syncprocedure. For Dual Connectivity operation the term SpCell (i.e. SpecialCell) refers to the PCell of the MCG or the PSCell of the SCG, otherwisethe term Special Cell refers to the PCell.

In the fifth generation wireless communication system (or NR), PhysicalDownlink Control Channel (PDCCH) is used to schedule downlink (DL)transmissions on Physical Downlink Shared Channel (PDSCH) and uplink(UL) transmissions on Physical Uplink Shared Channel (PUSCH). TheDownlink Control Information (DCI) on PDCCH includes: Downlinkassignments containing at least modulation and coding format, resourceallocation, and hybrid automatic repeat request (HARQ) informationrelated to downlink shared channel (DL-SCH); and Uplink schedulinggrants containing at least modulation and coding format, resourceallocation, and hybrid-ARQ information related to uplink shared channel(UL-SCH). In addition to scheduling, PDCCH can be used to activation anddeactivation of configured PUSCH transmission with configured grant;activation and deactivation of PDSCH semi-persistent transmission;notifying one or more UEs of the slot format; notifying one or more UEsof the physical resource block(s) (PRB(s)) and orthogonal frequencydivision multiplexing (OFDM) symbol(s) where the UE may assume notransmission is intended for the UE; transmission of transmission powercontrol (TPC) commands for Physical Uplink Control Channel (PUCCH) andPUSCH; transmission of one or more TPC commands for sounding referencesignal (SRS) transmissions by one or more UEs; switching a UE's activebandwidth part; and initiating a random access procedure.

A UE monitors a set of PDCCH candidates in the configured monitoringoccasions in one or more configured COntrol REsource SETs (CORESETs)according to the corresponding search space configurations. A CORESETconsists of a set of PRBs with a time duration of 1 to 3 OFDM symbols.The resource units Resource Element Groups (REGs) and Control ChannelElements (CCEs) are defined within a CORESET with each CCE consisting aset of REGs. Control channels are formed by aggregation of CCE.Different code rates for the control channels are realized byaggregating different number of CCE. Interleaved and non-interleavedCCE-to-REG mapping are supported in a CORESET. Polar coding is used forPDCCH. Each resource element group carrying PDCCH carries its owndemodulation reference signal (DMRS). Quadrature phase shift keying(QPSK) modulation is used for PDCCH.

In NR, a list of search space configurations are signaled by gNB foreach configured bandwidth part (BWP) wherein each search configurationis uniquely identified by an identifier. Identifiers of search spaceconfiguration to be used for a specific purpose such as pagingreception, system information (SI) reception, random access response(RAR) reception is explicitly signaled by gNB. In NR search spaceconfiguration comprises parameters Monitoring-periodicity-PDCCH-slot,Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot, andduration. A UE determines PDCCH monitoring occasion(s) within a slotusing the parameters PDCCH monitoring periodicity(Monitoring-periodicity-PDCCH-slot), the PDCCH monitoring offset(Monitoring-offset-PDCCH-slot), and the PDCCH monitoring pattern(Monitoring-symbols-PDCCH-within-slot). PDCCH monitoring occasions arethere in slots ‘x’ to x+duration where the slot with number ‘x’ in aradio frame with number ‘y’ satisfies the Equation 1 below:

(y*(number of slots in a radioframe)+x−Monitoring-offset-PDCCH-slot)mod(Monitoring-periodicity-PDCCH-slot)=0;  Equation1

The starting symbol of a PDCCH monitoring occasion in each slot havingPDCCH monitoring occasion is given byMonitoring-symbols-PDCCH-within-slot. The length (in symbols) of a PDCCHmonitoring occasion is given in the corset associated with the searchspace. search space configuration includes the identifier of CORESETconfiguration associated with it. A list of CORESET configurations aresignaled by gNB for each configured BWP wherein each CORESETconfiguration is uniquely identified by an identifier. Note that eachradio frame is of 10 ms duration. Radio frame is identified by a radioframe number or system frame number. Each radio frame comprises severalslots wherein the number of slots in a radio frame and duration of slotsdepends on sub carrier spacing. The number of slots in a radio frame andduration of slots depends radio frame for each supported subcarrierspacing (SCS) is pre-defined in NR. Each CORESET configuration isassociated with a list of TCI (Transmission configuration indicator)states. One DL reference signal (RS) identifier (ID) (SSB or channelstate information reference signal (CSI-RS)) is configured per TCIstate. The list of TCI states corresponding to a CORESET configurationis signaled by gNB via RRC signaling. One of the TCI states in the TCIstate list is activated and indicated to UE by gNB. TCI state indicatesthe DL TX beam (DL TX beam is quasi-collocated (QCLed) with SSB/CSI RSof TCI state) used by GNB for transmission of PDCCH in the PDCCHmonitoring occasions of a search space.

In NR bandwidth adaptation (BA) is supported. With BA, the receive andtransmit bandwidth of a UE need not be as large as the bandwidth of thecell and can be adjusted: the width can be ordered to change (e.g., toshrink during period of low activity to save power); the location canmove in the frequency domain (e.g., to increase scheduling flexibility);and the subcarrier spacing can be ordered to change (e.g., to allowdifferent services). A subset of the total cell bandwidth of a cell isreferred to as a Bandwidth Part (BWP).

BA is achieved by configuring RRC connected UE with BWP(s) and tellingthe UE which of the configured BWPs is currently the active one. When BAis configured, the UE only has to monitor PDCCH on the one active BWP(i.e., the UE does not have to monitor PDCCH on the entire DL frequencyof the serving cell). In RRC connected state, the UE is configured withone or more DL and UL BWPs, for each configured Serving Cell (i.e. PCellor SCell). For an activated Serving Cell, one UL and DL BWP is alwaysactive at any point in time. The BWP switching for a Serving Cell isused to activate an inactive BWP and deactivate an active BWP at a time.The BWP switching is controlled by the PDCCH indicating a downlinkassignment or an uplink grant, by the bwp-InactivityTimer, by RRCsignaling, or by the medium access control (MAC) entity itself uponinitiation of Random Access procedure. Upon addition of SpCell oractivation of an SCell, the DL BWP and UL BWP indicated byfirstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id respectively isactive without receiving PDCCH indicating a downlink assignment or anuplink grant. The active BWP for a Serving Cell is indicated by eitherRRC or PDCCH. For unpaired spectrum, a DL BWP is paired with a UL BWP,and BWP switching is common for both UL and DL. Upon expiry of BWPinactivity timer UE switch to the active DL BWP to the default DL BWP orinitial DL BWP (if default DL BWP is not configured).

In the 5G wireless communication system, random access (RA) issupported. Random access (RA) is used to achieve uplink (UL) timesynchronization. RA is used during initial access, handover, RRCconnection re-establishment procedure, scheduling request transmission,SCG addition/modification, beam failure recovery and data or controlinformation transmission in UL by non-synchronized UE in RRC CONNECTEDstate. Several types of random access procedure is supported.

Contention based random access (CBRA): This is also referred as 4 stepCBRA. In this type of random access, the UE first transmits RandomAccess preamble (also referred as Msg1) and then waits for Random accessresponse (RAR) in the RAR window. RAR is also referred as Msg2. The nextgeneration node B (gNB) transmits the RAR on PDSCH. PDCCH scheduling thePDSCH carrying RAR is addressed to RA-radio network temporary identifier(RA-RNTI). RA-RNTI identifies the time-frequency resource (also referredas physical RA channel (PRACH) occasion or PRACH transmission (TX)occasion or RA channel (RACH) occasion) in which RA preamble wasdetected by gNB. The RA-RNTI is calculated as follows:RA-RNTI=1+s_id+14*t_id+14*80*f_id+14*80*8*ul_carrier_id, where s_id isthe index of the first orthogonal frequency division multiplexing (OFDM)symbol of the PRACH occasion where UE has transmitted Msg1, i.e. RApreamble; 0≤s_id≤14; t_id is the index of the first slot of the PRACHoccasion (0≤t_id<80); fid is the index of the PRACH occasion within theslot in the frequency domain (0≤f_id<8), and ul_carrier_id is the ULcarrier used for Msg1 transmission (0 for normal UL (NUL) carrier and 1for supplementary UL (SUL) carrier. Several RARs for various Randomaccess preambles detected by the gNB can be multiplexed in the same RARMAC protocol data unit (PDU) by the gNB. An RAR in a MAC PDU correspondsto the UE's RA preamble transmission if the RAR includes an RA preambleidentifier (RAPID) of RA preamble transmitted by the UE. If the RARcorresponding to its RA preamble transmission is not received during theRAR window and the UE has not yet transmitted the RA preamble for aconfigurable number of times (configured by the gNB in RACHconfiguration), the UE goes back to first step (i.e., select randomaccess resource (preamble/RACH occasion)) and transmits the RA preamble.A backoff may be applied before going back to the first step.

If the RAR corresponding to its RA preamble transmission is received,the UE transmits a message 3 (Msg3) in UL grant received in RAR. TheMsg3 includes messages such as RRC connection request, RRC connectionre-establishment request, RRC handover confirm, scheduling request, SIrequest etc. The Msg3 may also include the UE identity (i.e., cell-radionetwork temporary identifier (C-RNTI) or system architecture evolution(SAE)-temporary mobile subscriber identity (S-TMSI) or a random number).After transmitting the Msg3, the UE starts a contention resolutiontimer. While the contention resolution timer is running, if the UEreceives a PDCCH addressed to C-RNTI included in Msg3, contentionresolution is considered successful, the contention resolution timer isstopped, and the RA procedure is completed. While the contentionresolution timer is running, if the UE receives a contention resolutionMAC control element (CE) including the UE's contention resolutionidentity (first X bits of common control channel (CCCH) service dataunit (SDU) transmitted in Msg3), contention resolution is consideredsuccessful, the contention resolution timer is stopped, and the RAprocedure is completed. If the contention resolution timer expires andthe UE has not yet transmitted the RA preamble for a configurable numberof times, UE goes back to the first step (i.e., select random accessresource (preamble/RACH occasion)), and transmits the RA preamble. Abackoff may be applied before going back to first step.

Contention free random access (CFRA): This is also referred as legacyCFRA or 4 step CFRA. The CFRA procedure is used for scenarios such ashandover where low latency is required, timing advance establishment forSCell, etc. The evolved node B (eNB) assigns a dedicated Random accesspreamble to the UE. UE transmits the dedicated RA preamble. The eNBtransmits the RAR on PDSCH addressed to RA-RNTI. The RAR conveys RApreamble identifier and timing alignment information. The RAR may alsoinclude UL grant. The RAR is transmitted in RAR window similar to CBRAprocedure. CFRA is considered successfully completed after receiving theRAR including RAPID of the RA preamble transmitted by the UE. In case RAis initiated for beam failure recovery, CFRA is considered successfullycompleted if a PDCCH addressed to C-RNTI is received in a search spacefor beam failure recovery. If the RAR window expires, and RA is notsuccessfully completed and the UE has not yet transmitted the RApreamble for a configurable number of times (configured by gNB in RACHconfiguration), the UE retransmits the RA preamble.

For certain events such has handover and beam failure recovery ifdedicated preamble(s) are assigned to UE, during first step of randomaccess (i.e., during random access resource selection for Msg1transmission), the UE determines whether to transmit dedicated preambleor non-dedicated preamble. Dedicated preambles are typically providedfor a subset of SSBs/CSI-RSs. If there is no SSB/CSI-RS having a DLreference signal received power (RSRP) above a threshold among theSSBs/CSI-RSs for which contention free random access resources (i.e.dedicated preambles/ROs) are provided by the gNB, the UE selects anon-dedicated preamble. Otherwise, the UE selects a dedicated preamble.So during the RA procedure, one random access attempt can be CFRA whileother random access attempts can be CBRA.

2 step contention based random access (2 step CBRA): In the first step,UE transmits a random access preamble on PRACH and a payload (i.e. MACPDU) on PUSCH. The random access preamble and payload transmission isalso referred as MsgA. In the second step, after MsgA transmission, theUE monitors for a response from the network (i.e. gNB) within aconfigured window. The response is also referred as MsgB. If a CCCH SDUwas transmitted in MsgA payload, the UE performs contention resolutionusing the contention resolution information in MsgB. The contentionresolution is successful if the contention resolution identity receivedin MsgB matches the first 48 bits of the CCCH SDU transmitted in MsgA.If C-RNTI was transmitted in MsgA payload, the contention resolution issuccessful if the UE receives PDCCH addressed to C-RNTI. If contentionresolution is successful, the random access procedure is consideredsuccessfully completed. Instead of contention resolution informationcorresponding to the transmitted MsgA, MsgB may include fallbackinformation corresponding to the random access preamble transmitted inMsgA. If the fallback information is received, UE transmits Msg3 andperforms contention resolution using Msg4 as in CBRA procedure. Ifcontention resolution is successful, the random access procedure isconsidered successfully completed. If contention resolution fails uponfallback (i.e. upon transmitting Msg3), the UE retransmits MsgA. If aconfigured window in which the UE monitors network response aftertransmitting MsgA expires and the UE has not received MsgB includingcontention resolution information or fallback information as explainedabove, the UE retransmits MsgA. If the random access procedure is notsuccessfully completed even after transmitting the MsgA configurablenumber of times, UE fallbacks to 4 step RACH procedure i.e. UE onlytransmits the PRACH preamble.

MsgA payload may include one or more of a CCCH SDU, a dedicated controlchannel (DCCH) SDU, a dedicated traffic channel (DTCH) SDU, a bufferstatus report (BSR) MAC CE, a power headroom report (PHR) MAC CE, SSBinformation, a C-RNTI MAC CE, or padding. The MsgA may include a UE ID(e.g. random ID, S-TMSI, C-RNTI, resume ID, etc.) along with thepreamble in the first step. The UE ID may be included in the MAC PDU ofthe MsgA. A UE ID such as C-RNTI may be carried in the MAC CE, whereinthe MAC CE is included in MAC PDU. Other UE IDs (such as random ID,S-TMSI, C-RNTI, resume ID, etc.) may be carried in CCCH SDU. The UE IDcan be one of random ID, S-TMSI, C-RNTI, resume ID, IMSI, idle mode ID,inactive mode ID, etc. The UE ID can be different in different scenariosin which UE performs the RA procedure. When the UE performs RA afterpower on (before it is attached to the network), then the UE ID is therandom ID. When the UE performs RA in IDLE state after the UE isattached to network, then the UE ID is S-TMSI. If UE has an assignedC-RNTI (e.g. in connected state), the UE ID is C-RNTI. In case the UE isin INACTIVE state, the UE ID is resume ID. In addition to UE ID, someaddition ctrl information can be sent in MsgA. The control informationmay be included in the MAC PDU of the MsgA. The control information mayinclude one or more of connection request indication, connection resumerequest indication, SI request indication, buffer status indication,beam information (e.g. one or more DL TX beam ID(s) or SSB ID(s)), beamfailure recovery indication/information, data indicator, cell/BS/TRPswitching indication, connection re-establishment indication,reconfiguration complete or handover complete message, etc.

2 step contention free random access (2 step CFRA): In this case, thegNB assigns dedicated Random access preamble(s) and PUSCH resource(s) tothe UE for MsgA transmission. RO(s) to be used for preamble transmissionmay also be indicated. In the first step, the UE transmits random accesspreamble on PRACH and a payload on PUSCH using the contention freerandom access resources (i.e., dedicated preamble/PUSCH resource/RO). Inthe second step, after MsgA transmission, the UE monitors for a responsefrom the network (i.e., gNB) within a configured window. If the UEreceives PDCCH addressed to C-RNTI, random access procedure isconsidered successfully completed. If the UE receives fallbackinformation corresponding to its transmitted preamble, random accessprocedure is considered successfully completed.

For certain events such has handover and beam failure recovery ifdedicated preamble(s) and PUSCH resource(s) are assigned to UE, duringthe first step of random access (i.e., during random access resourceselection for MsgA transmission), the UE determines whether to transmita dedicated preamble or a non-dedicated preamble. Dedicated preamblesare typically provided for a subset of SSBs/CSI-RSs. If there is noSSB/CSI-RS having DL RSRP above a threshold amongst the SSBs/CSI-RSs forwhich contention free random access resources (i.e., dedicatedpreambles/ROs/PUSCH resources) are provided by the gNB, the UE selects anon dedicated preamble. Otherwise UE select dedicated preamble. Soduring the RA procedure, one random access attempt can be 2 step CFRAwhile other random access attempt can be 2 step CBRA.

Upon initiation of random access procedure, the UE first selects thecarrier (SUL or NUL). If the carrier to use for the Random Accessprocedure is explicitly signaled by the gNB, the UE selects the signaledcarrier for performing Random Access procedure. If the carrier to usefor the Random Access procedure is not explicitly signaled by gNB, ifthe Serving Cell for the Random Access procedure is configured withsupplementary uplink, and if the RSRP of the downlink pathloss referenceis less than rsrp-ThresholdSSB-SUL, then the UE selects the SUL carrierfor performing Random Access procedure. Otherwise, the UE selects theNUL carrier for performing Random Access procedure. Upon selecting theUL carrier, the UE determines the UL and DL BWP for random accessprocedure as specified in section 5.15 of TS 38.321. The UE thendetermines whether to perform 2 step or 4 step RACH for this randomaccess procedure.

-   -   If this random access procedure is initiated by PDCCH order and        if the ra-PreambleIndex explicitly provided by PDCCH is not        0b000000, UE selects 4 step RACH.    -   else if 2 step contention free random access resources are        signaled by gNB for this random access procedure, then the UE        selects 2 step RACH.    -   else if 4 step contention free random access resources are        signaled by gNB for this random access procedure, then the UE        selects 4 step RACH.    -   else if the UL BWP selected for this random access procedure is        configured with only 2 step RACH resources, then the UE selects        2 step RACH.    -   else if the UL BWP selected for this random access procedure is        configured with only 4 step RACH resources, then the UE selects        4 step RACH.    -   else if the UL BWP selected for this random access procedure is        configured with both 2 step and 4 step RACH resources,        -   if RSRP of the downlink pathloss reference is below a            configured threshold, then the UE selects 4 step RACH.            Otherwise UE selects 2 step RACH.

In the fifth generation wireless communication system, node B (gNB) orbase station in cell broadcast Synchronization Signal and PBCH block(SSB) consists of primary synchronization signal (PSS) and secondarysynchronization signal (SSS) and system information. System information(SI) includes common parameters needed to communicate in cell. In thefifth generation wireless communication system (also referred as nextgeneration radio or NR), SI is divided into the master information block(MIB) and a number of system information blocks (SIBs) where:

-   -   the MIB is always transmitted on the BCH with a periodicity of        80 ms and repetitions made within 80 ms and includes parameters        that are needed to acquire system information block 1 (SIB1)        from the cell.    -   the SIB1 is transmitted on the DL-SCH with a periodicity of 160        ms and variable transmission repetition. The default        transmission repetition periodicity of SIB1 is 20 ms but the        actual transmission repetition periodicity is up to network        implementation. The scheduling information in SIB 1 includes        mapping between SIBs and SI messages, periodicity of each SI        message and SI window length. The scheduling information in SIB        1 includes an indicator for each SI message, which indicates        whether the concerned SI message is being broadcasted or not. If        at least one SI message is not being broadcasted, SIB1 may        include random access resources (PRACH preamble(s) and PRACH        resource(s)) for requesting gNB to broadcast one or more SI        message(s).    -   SIBs other than SIB1 are carried in SystemInformation (SI)        messages, which are transmitted on the DL-SCH. Only SIBs having        the same periodicity can be mapped to the same SI message. Each        SI message is transmitted within periodically occurring time        domain windows (referred to as SI-windows with same length for        all SI messages). Each SI message is associated with a SI-window        and the SI-windows of different SI messages do not overlap.        Within one SI-window only the corresponding SI message is        transmitted. Any SIB except SIB1 can be configured to be cell        specific or area specific, using an indication in SIB1. The cell        specific SIB is applicable only within a cell that provides the        SIB while the area specific SIB is applicable within an area        referred to as SI area, which consists of one or several cells        and is identified by systemInformationAreaID.

In the fifth generation wireless communication system, RRC can be in oneof the following states: RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED. A UEis either in RRC_CONNECTED state or in RRC_INACTIVE state when an RRCconnection has been established. If this is not the case, i.e. no RRCconnection is established, the UE is in RRC_IDLE state. The RRC statescan further be characterized as follows:

In the RRC_IDLE, a UE specific discontinuous (DRX) may be configured byupper layers. The UE monitors Short Messages transmitted with pagingRNTI (P-RNTI) over DCI; monitors a Paging channel for CN paging using5G-S-temporary mobile subscriber identity (5G-S-TMSI); performsneighboring cell measurements and cell (re-)selection; acquires systeminformation and can send SI request (if configured); performs logging ofavailable measurements together with location and time for loggedmeasurement configured UEs.

In RRC_INACTIVE, a UE specific DRX may be configured by upper layers orby RRC layer, the UE stores the UE Inactive AS context, and a RAN-basednotification area is configured by RRC layer. The UE monitors ShortMessages transmitted with P-RNTI over DCI; monitors a Paging channel forCN paging using 5G-S-TMSI and RAN paging using full I-RNTI; performsneighboring cell measurements and cell (re-)selection; performsRAN-based notification area updates periodically and when moving outsidethe configured RAN-based notification area; acquires system informationand can send SI request (if configured); and performs logging ofavailable measurements together with location and time for loggedmeasurement configured UEs.

In the RRC_CONNECTED, the UE stores the AS context and transfer ofunicast data to/from UE takes place. The UE monitors Short Messagestransmitted with P-RNTI over DCI, if configured; monitors controlchannels associated with the shared data channel to determine if data isscheduled for it; provides channel quality and feedback information;performs neighboring cell measurements and measurement reporting; andacquires system information.

In the RRC_CONNECTED, network may initiate suspension of the RRCconnection by sending RRCRelease with suspend configuration. When theRRC connection is suspended, the UE stores the UE Inactive AS contextand any configuration received from the network, and transits toRRC_INACTIVE state. If the UE is configured with SCG, the UE releasesthe SCG configuration upon initiating a RRC Connection Resume procedure.The RRC message to suspend the RRC connection is integrity protected andciphered.

The resumption of a suspended RRC connection is initiated by upperlayers when the UE needs to transit from RRC_INACTIVE state toRRC_CONNECTED state or by RRC layer to perform a RAN based notificationarea (RNA) update or by RAN paging from NG-RAN. When the RRC connectionis resumed, network configures the UE according to the RRC connectionresume procedure based on the stored UE Inactive AS context and any RRCconfiguration received from the network. The RRC connection resumeprocedure re-activates AS security and re-establishes signaling radiobearer(s) (SRB(s)) and data radio bearer(s) (DRB(s)). In response to arequest to resume the RRC connection, the network may resume thesuspended RRC connection and send the UE to RRC_CONNECTED, or reject therequest to resume and send the UE to RRC_INACTIVE (with a wait timer),or directly re-suspend the RRC connection and send the UE toRRC_INACTIVE, or directly release the RRC connection and send the UE toRRC_IDLE, or instruct the UE to initiate NAS level recovery (in thiscase the network sends an RRC setup message).

 Upon initiating the resume procedure, the UE:  - applies the default L1parameter values as specified in corresponding physical layerspecifications, except for the parameters for which values are providedin SIB1;  - applies the default MAC Cell Group configuration  - appliesthe CCCH configuration  - starts the timer T319;  - applies thetimeAlignmentTimerCommon included in SIB1  - applies the default SRB1configuration  - sets the variable pendingRNA-Update to false;  -initiates transmission of the RRCResumeRequest message orRRCResumeRequest1  - restores the RRC configuration, RoHC state, thestored QoS flow to DRB mapping rules and the KgNB and K_(RRCint) keysfrom the stored UE Inactive AS context except for the following: *masterCellGroup; * mrdc-SecondaryCellGroup, if stored; and *pdcp-Config;  - sets the resumeMAC-I to the 16 least significant bits ofthe MAC-I calculated: * over the ASN.1 encoded as per clause 8 (i.e., amultiple of 8 bits) VarResumeMAC-Input; * with the K_(RRCint) key in theUE Inactive AS Context and the previously configured integrityprotection algorithm; and * with all input bits for COUNT, BEARER andDIRECTION set to binaiy ones;  - derives the KgNB key based on thecurrent KgNB key or the NH, using the stored nextHopChainingCount value; - derives the K_(RRCenc) key, the K_(RRCint) key, the K_(UPint) key andthe  K_(UPenc) key;  - configures lower layers to apply integrityprotection for all signaling radio bearers except SRB0 using theconfigured algorithm and the K_(RRCint) key and K_(UPint) key, i.e.,integrity protection shall be applied to all subsequent messagesreceived and sent by the UE;  - configures lower layers to applyciphering for all signaling radio bearers except SRB0 and to apply theconfigured ciphering algorithm, the K_(RRCenc) key and the K_(UPenc) keyderived, i.e. the ciphering configuration shall be applied to allsubsequent messages received and sent by the UE;  - re-establishes PDCPentities for SRB1;  - resumes SRB1; and  - transmits RRCResumeRequest orRRCResumeRequest1.

In the 4G wireless communication system, for small data transmission inRRC_IDLE, the UE can be configured with preconfigured UL resources. TheUE receives PUSCH resources (e.g., periodic UL grants) for small datatransmission in RRC connection release message. If the UE has a smallamount of data to transmit in RRC_IDLE, the UE is camped in the samecell from which the UE has received UL grants in the RRC connectionrelease message, and the UE has a valid TA, then the UE selects theearliest UL grant and transmits the MAC PDU in the selected UL grant.The UE waits for response from the network within a configured timeinterval. For the response, the UE monitors PDCCH addressed to an RNTIassigned to UE in RRC connection release message. If the response is notreceived, small data transmission is considered to have failed.

5G wireless communication system supports multiple beams, multiple ULcarriers, multiple BWPs and search spaces for PDCCH monitoring. Not allthese aspects are considered in the existing procedure. The small datatransmission procedure should be enhanced to support multiple beams,multiple UL carriers, multiple BWPs and search spaces for PDCCHmonitoring.

In the 5G wireless communication system, logical channel prioritization(LCP) procedure is used to generate MAC PDU. RRC controls the LCPprocedure by configuring mapping restrictions for each logical channel:

-   -   allowedSCS-List, which sets the allowed Subcarrier Spacing(s)        for transmission;    -   maxPUSCH-Duration, which sets the maximum PUSCH duration allowed        for transmission;    -   configuredGrantType1Allowed, which sets whether a configured        grant Type 1 can be used for transmission;    -   allowedServingCells, which sets the allowed cell(s) for        transmission;    -   allowedCG-List, which sets the allowed configured grant(s) for        transmission;    -   allowedPHY-PriorityIndex, which sets the allowed PHY priority        index(es) of a dynamic grant for transmission.

For SDT, DRBs are resumed upon initiation of RRC connection resumption.The issue is whether the LCH restrictions in the stored AS-context areapplied during MAC PDU generation for small data transmission or not.

Embodiment 1—Operation Upon Initiating Resumption of RRC Connection forSmall Data Transmission in RRC_INACTIVE or Operation Upon InitiatingSmall Data Transmission Procedure in RRC_INACTIVE

The UE is in RRC_INACTIVE state. During the RRC_INACTIVE state, the UEinitiates RRC connection resumption for small data transmission (ifcriteria to perform small data transmission is met). The RRC connectionresumption for small data transmission may also be referred as smalldata transmission procedure. Upon initiation of RRC connectionresumption for small data transmission or upon initiation of small datatransmission procedure, the UE performs the following operations:

 - apply the default L1 parameter values as specified in correspondingphysical layer specifications, except for the parameters for whichvalues are provided in SIB1;  - apply the default MAC Cell Groupconfiguration  - apply the CCCH configuration  - start timer (T319 or anew timer configured by gNB for small data transmission);  - apply thetimeAlignmentTimerCommon included in SIB1  - apply the default SRB1configuration  - set the variable pendingRNA-Update to false;  -initiate transmission of the RRCResumeRequest message orRRCResumeRequest1  - if field useFullResumeID is signalled in SIB1: *select RRCResumeRequest1 as the message to use; * set the resumeIdentityto the stored fullI-RNTI value;  - else: * select RRCResumeRequest asthe message to use; * set the resumeIdentity to the stored shortI-RNTIvalue;  - restore the RRC configuration, RoHC state, the stored QoS flowto DRB mapping rules and the KgNB and K_(RRCint) keys from the stored UEInactive AS context except for the following: * masterCellGroup; *mrdc-SecondaryCellGroup, if stored; and * pdcp-Config;  - set theresumeMAC-I to the 16 least significant bits of the MAC-I calculated: *over the ASN.1 encoded VarResumeMAC-Input * with the K_(RRCint) key inthe UE Inactive AS Context and the previously configured integrityprotection algorithm; and * with all input bits for COUNT, BEARER andDIRECTION set to binary ones;  - derive the KgNB key based on thecurrent KgNB key or the NH, using the stored nextHopChainingCount value; - derive the K_(RRCenc) key, the K_(RRCint) key, the K_(UPint) key andthe  K_(UPenc) key;  - configure lower layers to apply integrityprotection for all radio bearers except SRB0 using the configuredalgorithm and the K_(RRCint) key and K_(UPint) key, i.e., integrityprotection shall be applied to all subsequent messages and user datareceived and sent by the UE; only DRBs with previously configured UPintegrity protection shall resume integrity protection.

-   -   configure lower layers to apply ciphering for all radio bearers        except SRB0 and to apply the configured ciphering algorithm, the        K_(RRCenc) key and the K_(UPenc) key derived, i.e. the ciphering        configuration shall be applied to all subsequent messages and        data received and sent by the UE;    -   re-establish PDCP entities for all SRBs and all DRBs (or        re-establish PDCP entities for SRB1 and all DRBs); Note that UE        applies the PDCP configuration from stored AS context for the        re-established PDCP entities of DRBs and SRB2. In an embodiment,        whether to apply PDCP configuration from stored AS context or        apply default PDCP configuration may be indicated by gNB in        RRCRelease message or RRCReconfiguration message and UE applies        PDCP configuration from stored AS context or apply default PDCP        configuration accordingly for the re-established PDCP entities        of DRBs and SRB2.    -   re-establish RLC entities for DRBs (note that RLC entities for        SRB1 is re-established when UE enters inactive state). Note that        the UE applies the RLC configuration from a stored AS context        for the re-established RLC entities of DRBs and SRB2. In an        embodiment, whether to apply RLC configuration from the stored        AS context or to apply a default RLC configuration can be        indicated by the gNB in the RRCRelease message or the        RRCReconfiguration message, and the UE applies the RLC        configuration from the stored AS context or applies the default        RLC configuration accordingly for the re-established RLC        entities of DRBs and SRB2.    -   resume all SRBs and all DRBs (or resume SRB1 and all DRBs);        -   Upon connection resume, at which point of time will PDCP            provide DTCH SDU to the lower layer, also needs to be            specified. RRC can indicate this to PDCP upon resumption of            DRBs.    -   transmit RRCResumeRequest or RRCResumeRequest1. The user data        are ciphered and integrity protected (only for DRBs configured        with UP integrity protection) and transmitted on DTCH        multiplexed with the RRCResumeRequest/RRCResumeRequest1 message        on CCCH. Some assistance information may also be included like        BSR (regular or truncated); a New MAC CE indicating UE has more        UL data or UE expects DL data in response to UL Data and/or        including SS-RSRP or CQI; or an indication in the RRC message        indicating that the UE has more UL data or that the UE expects        DL data in response to UL Data. Note that this transmission is        performed in Msg3 or MsgA in case of RACH based small data        transmission and in preconfigured UL grant in case of non RACH        based small data transmission.    -   In an alternate embodiment, instead of sending RRCResumeRequest        or RRCResumeRequest1 together with uplink data, uplink data with        integrity protection is transmitted. RRCResumeRequest or        RRCResumeRequest1 message is not transmitted. The gNB may        authenticate UE based on received MAC-I together with uplink        data. Note that this transmission is performed in Msg3 or MsgA        in case of RACH based small data transmission and in        preconfigured UL grant in case of non RACH based small data        transmission.

Instead of resuming all DRBs and re-establishing PDCP/RLC entities forall DRBs in the above operation, the UE resumes and re-establishes onlythose DRBs for which small data transmission is allowed.

-   -   The DRBs for which small data transmission is allowed can be        signaled by the gNB (e.g., in an RRCRelease message or any other        RRC signaling message). One or more DRB identities of DRBs for        which small data transmission is allowed may be included in        RRCRelease message or any other RRC signaling message, such as        an RRCReconfiguration message. Alternately, an indicator (e.g.,        SDTAllowed set to TRUE) may be included in a configuration of        DRB which indicates that SDT is allowed for that DRB. If        SDTAllowed is set to FALSE or is not included, UE assumes that        SDT is not allowed for that DRB.    -   In an embodiment, a DRB is considered as allowed for small data        transmission if data from LCH of this DRB is allowed to be        transmitted according to LCH restrictions (allowedSCS-List,        maxPUSCH-Duration, configuredGrantType1Allowed,        allowedServingCells, allowedCG-List and        allowedPHY-PriorityIndex) in the UL grant for small data        transmission. One or more LCH restrictions are configured in LCH        configuration of LCH associated with DRB. allowedSCS-List sets        the allowed Subcarrier Spacing(s) for transmission, including        maxPUSCH-Duration, which sets the maximum PUSCH duration allowed        for transmission; configuredGrantType1Allowed, which sets        whether a configured grant Type 1 can be used for transmission;        allowedServingCells, which sets the allowed cell(s) for        transmission; allowedCG-List, which sets the allowed configured        grant(s) for transmission; and allowedPHY-PriorityIndex, which        sets the allowed PHY priority index(es) of a dynamic grant for        transmission. For example, if SCS for UL grant for small data        transmission is SCS X and LCH for a DRB is configured with        allowedSCS-List wherein SCS X is not included in        allowedSCS-List, the DRB is not considered for small data        transmission.

Embodiment 2—Small Data Transmission Using Preconfigured UL Grant

FIG. 1 illustrates an example of small data transmission usingpre-configured uplink grant (can also be referred as CG type 1 PUSCHresources) according to an embodiment of the disclosure.

Referring to FIG. 1, in RRC_CONNECTED UE reports its capabilities toindicate whether to support pre-configured PUSCH during RRC_INACTIVE. UEmay report its preference to configure the pre-configured PUSCH e.g. inUEAssistanceInformation message. The gNB decides to configurepre-configured PUSCH in RRC_INACTIVE based on: UE capabilities, UEtypes, UE preference and UL traffic pattern.

The UE receives the pre-configured PUSCH resources (e.g. CG Type 1resources) for small data transmission (SDT) in dedicated signaling(RRCReconfiguration message or RRCRelease message) from gNB at operation110.

-   -   In an embodiment, these PUSCH resources for SDT are applicable        to cell from which UE has received the RRCRelease message or        RRCReconfiguration message including PUSCH resources for SDT. In        an embodiment, these resources for SDT are applicable to        multiple cells. The details of association between UL resources        for SDT and cell(s) is described later.    -   These PUSCH resources are also mapped to SSB(s). The mapping        rule between PUSCH resources and SSBs is described later.    -   If multiple UL carriers are supported, pre-configured PUSCH        resources for SDT are received separately for SUL and NUL    -   The configuration on pre-configured PUSCH is provided in        RRCRelease. For instance, the configuration can be added when        RRCRelease is used to switch to RRC_INACTIVE. The configuration        may be added into SuspendConfig IE. Alternately, the        ConfiguredGrantConfig on Type 1 is provided in        RRCReconfiguration. And, an indicator is included into        RRCRelease to indicate if UE can continue to use the configured        grant type 1 during RRC_INACTIVE. In addition, additional        (Pre-configured PUSCH specific) configuration may be provided in        RRCRelease.

While the UE is in RRC_INACTIVE, SDT using pre-configured PUSCHresources is initiated at operation 120. Criteria for SDT usingpre-configured PUSCH resources is described later.

The UE selects UL carrier at operation 130.

-   -   If SUL is configured (in the cell where UE is performing SDT        i.e. camped cell in RRC_INACTIVE) and the RSRP of the downlink        pathloss reference (e.g., SSB) is less than        RSRPThresholdSUL-SDT, the UE selects SUL. Otherwise, the UE        selects NUL. RSRPThresholdSUL-SDT is received from gNB. If        RSRPThresholdSUL-SDT is not configured, the UE uses        RSRPThresholdSUL configured in RACH configuration. Note that        RSRPThresholdSUL-SDT is a new parameter configured for selecting        between SUL and NUL for small data transmission. This parameter        is different from SUL and NUL carrier selection for random        access preamble transmission. The reason is that UL information        transmitted in case of SDT is much larger than in case of normal        random access procedure for connection setup/resume and requires        a much robust channel condition to ensure reliable transmission.

The UE then selects an SSB with SS-RSRP above the RSRPThresholdSSB-SDTamong the SSBs associated with pre-configured PUSCH resources for SDT onselected UL carrier at operation 140. RSRPThresholdSSB-SDT is receivedfrom the gNB. If RSRPThresholdSSB-SDT is not configured, UE usesRSRPThresholdSSB configured in RACH configuration. Note that on theselected UL carrier, UE uses the pre-configured PUSCH resources for SDTon an UL BWP for small data transmission using pre-configured PUSCHresources. The UL BWP for small data transmission using pre-configuredPUSCH resources is described later.

The UE selects the earliest available UL grant corresponding to selectedSSB from the pre-configured PUSCH resources of selected UL carrier atoperation 150.

The UE generates MAC PDU for small data transmission and transmit in theselected UL grant at operation 160. The UE transmits the small data byusing one of the following options:

-   -   RRCResumeRequest (or new RRC message)+uplink data (on DTCH).        resumeIdentity, ResumeMAC-I, resumeCause in        RRCResumeRequest/RRCResumeRequest1. New resumeCause can be        introduced to indicate the small data transmission or small data        transmission via pre-configured PUSCH.    -   RRCResumeRequest (or new RRC message). resumeIdentity,        ResumeMAC-I, resumeCause, NAS container in        RRCResumeRequest/RRCResumeRequest1. NAS container includes UL        data.    -   new MAC CE (resumeIdentity, ResumeMAC-I)+uplink data (on DTCH).        resumeIdentity is provided for UE identification purpose.        ResumeMAC-I is for security.

Embodiment 2-1—Details of Pre-Configured PUSCH Resources for SDT

Associated Cell(s)

In an embodiment, pre-configured PUSCH resource configuration for SDTreceived in dedicated signaling are valid in the cell from which UE hasreceived the configuration.

In an embodiment, gNB can also signal preconfigured PUSCH resources forSDT for multiple cells in dedicated signalling.

-   -   Signalling can include preconfigured PUSCH resources        configuration (s) and associated one or more cell identities.    -   One configuration can be mapped to multiple cells.    -   Cell identity may be skipped for configuration associated with        cell from which RRCRelease message is received.

Associated BWP(s)

In an embodiment, pre-configured PUSCH resource configuration for SDTreceived in dedicated signaling are applied to initial UL BWP (orpre-configured PUSCH resource configuration for SDT are for the initialUL BWP or pre-configured PUSCH resource configuration for SDT aresignaled for initial UL BWP).

In an alternate embodiment, applicable BWP (among one of configured BWPsin RRCReconfiguration message, BWP ID can be indicated) for SDT usingpre-configured PUSCH resource configuration can be informed in RRCmessage (e.g., RRCRelease, RRCReconfiguration message or SI message). Inan embodiment, BWP configuration may include an indicator indicatingthat the BWP is applied for SDT using pre-configured PUSCH resourceconfiguration. In an embodiment, BWP for SDT using pre-configured PUSCHresource configuration is the BWP whose configuration includepre-configured PUSCH resource configuration for SDT. If applicable BWPis not informed, pre-configured PUSCH resource configuration for SDTreceived in dedicated signaling are applied to initial UL BWP.

Alternately, absolute value based frequency domain info can be signaled.

Associated UL Carrier(s)

In an embodiment, preconfigured PUSCH resources for SDT are separatelyconfigured for NUL and SUL.

In order to optimize the signalling, if configuration is same for bothSUL and NUL, the configuration for SUL can be skipped and UE applies theNUL configuration to SUL as well if SUL is configured in the cell.

Associated between SSBs and UL grants

In case of system deployed at higher frequencies, the UE needs to knowthe association between SSBs and configured grants (i.e., PUSCHoccasions/resources) configured.

In the RRC_INACTIVE state, the UE can only measure the SSBs, so theconfigured grants configured are associated with SSBs.

The following options are proposed in this disclosure for associatinggrants with SSBs:

-   -   Option 1: Signaling includes one configured grant configuration        for an UL carrier for SDT        -   1-1: list of one or more SSB Ids associated with a grant            configuration (or PUSCH resource configuration) is signaled.        -   1-2: grant configuration is associated with all transmitted            SSBs in the cell where transmitted SSBs are determined by            parameter ssb-PositionsInBurst.        -   In an embodiment, a UL grant is associated with ith SSB if            i=[floor(CURRENT_symbol/periodicity)] modulo N1, where            -   CURRENT_symbol=[SFN×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+slot                number in the frame×numberOfSymbolsPerSlot+symbol number                in the slot]            -   numberOfSlotsPerFrame and numberOfSymbolsPerSlot refer                to the number of consecutive slots per frame and the                number of consecutive symbols per slot respectively.                numberOfSlotsPerFrame is specific to SCS and is                pre-defined for each SCS. SCS is the SCS of UL BWP                associated with configured grant.            -   periodicity (in symbols) is the periodicity at which UL                grants are configured and is signaled            -   SFN is the system frame number in which configured UL                grant is allocated            -   slot number is the starting slot of configured UL grant            -   symbol number is the starting symbol of configured UL                grant            -   N1=Number of SSBs            -   SSBs are mapped in ascending order of their SSB IDs

FIG. 2 illustrates an example of association between synchronizationsignal block and uplink grant (PUSCH occasion/resource) according to anembodiment of the disclosure.

Referring to FIG. 2, UL grant/PUSCH occasion is associated with one SSB.The period over which each SSB is mapped to a UL grant/PUSCH occasioncan be referred as association period where association period ismultiple of configured grant periodicity. In FIG. 2, association periodincludes 4 periods configured grant. It is to be noted that each ULgrant/PUSCH occasion can be mapped to one or more SSBs. In FIG. 2, eachUL grant/PUSCH occasion is mapped to one SSB.

-   -   Option 2: Signaling includes multiple grant configurations for        an UL carrier        -   In this option, list of one or more SSB IDs associated with            a grant configuration is signaled in corresponding            configuration. Each UL grant in grant configuration is            associated with SSB(s) in the list.

FIG. 3 illustrates another example of association betweensynchronization signal block and uplink grant according to an embodimentof the disclosure.

Referring to FIG. 3, each grant configuration is mapped to one SSB. Soall UL grants/PUSCH occasions of that configured grant configuration aremapped to the same SSB. In case a grant configuration is mapped tomultiple SSBs, SSBs can be sequentially mapped to UL grants/PUSCHoccasions in sequentially manner as in FIG. 2. In case UL grants/PUSCHoccasions in a grant configuration are also frequency divisionmultiplexed, UL grants/PUSCH occasions can be sequentially first mappedin frequency and then in time.

Embodiment 2-2—Criteria to Determine Whether to Use Preconfigured PUSCHResource for SDT or not

The UE can perform SDT using preconfigured PUSCH resource (or CGresources) if following condition(s) are met. In different embodiments,a subset of below conditions can be applied.

Condition 1: the upper layers request resumption of an RRC connectionand the resumption request is for mobile originating calls and theestablishment cause is mo-Data; or the upper layers request resumptionof an RRC connection and the resumption request is for mobileoriginating calls; or and the resumption request is for mobileoriginating calls.

Condition 2: the UE supports SDT.

Condition 3: Preconfigured PUSCH resources are signaled in RRCReleasemessage with suspend indication during the preceding suspend procedureand UE is in same cell from which it has received Preconfigured PUSCHresources.

Condition 4: UE has a stored value of the nextHopChainingCount providedin the RRCRelease message with suspend indication during the precedingsuspend procedure. This condition can be skipped if nextHopChainingCountis always provided in RRCRelease message.

Condition 5: If the LCH restrictions for LCP are applied for SDT and allLCHs for which data is available for transmission is allowed to bemultiplexed in MAC PDU for Preconfigured PUSCH resource for SDTaccording to LCH restrictions.

Note that the Network can also indicate the DRBs for which SDT isallowed. In this case in Condition 5, LCHs corresponding to the DRBs forwhich SDT is allowed is considered. If data is available fortransmission for DRBs other than DRBs for which SDT is allowed, the UEshall initiate connection resume without SDT. In an embodiment Cond 5 isnot used for determining SDT or not.

Condition 6: UE has a valid TA value.

The network configures SDT-TimeAlignmentTimer. TheSDT-TimeAlignmentTimer is started upon receiving theSDT-TimeAlignmentTimer configuration from network. When a Timing AdvanceCommand MAC control element is received or PDCCH indicates timingadvance adjustment, the SDT-TimeAlignmentTimer is restarted.

-   -   If SDT-TimeAlignmentTimer is running; and    -   If the SS-RSRP (SS reference signal received power is the linear        average of the power contributions of the resource elements that        carry secondary synchronization signals) of pathloss reference        (i.e., SSB) has not increased by more than rsrp-IncreaseThresh        since the last time SDT-TimeAlignmentTimer was started; and    -   If the SS-RSRP of the pathloss reference (i.e., SSB) has not        decreased by more than rsrp-DecreaseThresh since the last time        SDT-TimeAlignmentTimer was started:        -   TA is considered valid. The SSB whose SS-RSRP is measured            for TA validation is amongst the SSBs transmitted in the            camped cell or the SSB whose SS-RSRP is measured for TA            validation is amongst the SSBs associated with the            Preconfigured PUSCH resources or the SSB whose SS-RSRP is            measured for TA validation is the SSB which is amongst the            SSBs associated with the Preconfigured PUSCH resources and            is also transmitted in camped cell. In case multiple such            SSBs exists, SS-RSRP of best SSB (i.e. one with highest            value of SS-RSRP) amongst such SSB can be used for TA            validation.    -   Condition 7: The UE has at least one SSB with SS-RSRP above a        threshold, among the SSBs associated with Preconfigured PUSCH        resources for UL carrier/UL BWP selected for SDT using        Preconfigured PUSCH resources. If the RSRP of the downlink        pathloss reference is less than rsrp-ThresholdSSB-SUL, SUL is        selected for SDT using Preconfigured PUSCH resources. Otherwise,        NUL is selected for SDT using Preconfigured PUSCH resources. In        an embodiment, Cond 7 is not used for determining SDT or not.

Condition 8: If the size of MAC PDU to be transmitted is less than orequal to transport block size (TBS) of Preconfigured PUSCH resource, orthe size of data available is less than or equal to data volumethreshold (data volume threshold is signaled by gNB). One of thefollowing options can be used to configure TBS for SDT usingPreconfigured PUSCH resource and to determine whether to PreconfiguredPUSCH resource for small data transmission or normal connection resume.

Embodiment 2-2-1—Option 1: Single PUSCH Configuration (for an UL Carrierof Camped Cell) and No Signal Quality Based Threshold

The gNB configures a single PUSCH configuration (for an UL carrier ofcamped cell) for SDT. The TBS is not explicitly signaled but determinedbased on SCS, number of PRBs and number of OFDM symbols of PUSCHresource. The TBS can also be explicitly signaled.

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH configuration        on UL carrier selected for transmission:

* UE initiate small data transmission using Preconfigured PUSCHresources.  - Else * UE does not initiate small data transmission usingPreconfigured PUSCH resources. UE may initiate small data transmissionusing RACH if RACH based criteria to perform SDT is met.

Embodiment 2-2-2—Option 2: Single PUSCH Configuration (for an UL Carrierof Camped Cell) and Single RSRP Threshold

The gNB configures a single PUSCH configuration (for an UL carrier ofcamped cell) for SDT. The TBS is not explicitly signaled but determinedbased on SCS, number of PRBs and number of OFDM symbols of PUSCHresource. The TBS can also be explicitly signaled. The gNB alsoconfigures the parameter sdt-Threshold. These parameters are separatelyconfigured for SUL and NUL as UL coverage is different for SUL and NUL.

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH configuration        on UL carrier selected for transmission and RSRP of the downlink        pathloss reference is greater than or equal to sdt-Threshold:

* UE initiate small data transmission using Preconfigured PUSCHresources.  - Else * UE does not initiate small data transmission usingPreconfigured PUSCH resources. UE may initiate small data transmissionusing RACH if RACH based criteria to perform SDT is met.

Embodiment 2-2-3—Option 3: Multiple [PUSCH Configuration, Threshold]

The gNB configures the parameter PUSCH-Config-SDT-1 andPUSCH-Config-SDT-2 PUSCH configuration (for an UL carrier of campedcell) for SDT. The TBS is not explicitly signaled but determined basedon SCS, number of PRBs and number of OFDM symbols of PUSCH resource. TheTBS can also be explicitly signaled. The sdt-Threshold-1 is alsoconfigured. These parameters are separately configured for SUL and NULas UL coverage is different for SUL and NUL.

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH-Config-SDT-1        for SDT on UL carrier selected for transmission:

* UE initiate small data transmission using Preconfigured PUSCHresources in PUSCH-Config-SDT-1.  - Else if the meassage size (UL dataavailable for transmission plus MAC header and, where required, MACcontrol elements) is less than equal to the TB size of payload accordingto PUSCH-Config-SDT-2 for the selected UL carrier and RSRP of thedownlink pathloss reference is greater than or equal tosdt-Threshold-2 * The UE initiates small data transmission usingPreconfigured PUSCH resources in PUSCH-Config-SDT-2.  - Else * The UEdoes not initiate small data transmission using Preconfigured PUSCHresources. UE may initiate small data transmission using RACH if RACHbased criteria to perform SDT is met.

This option can be generalized wherein gNB configures the parametersPUSCH-Config-SDT-1 to PUSCH-Config-SDT-N; sdt-Threshold-2 tosdt-Threshold-N

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH-Config-SDT-1        for SDT on UL carrier selected for transmission:        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-1.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        less than equal to the TB size of payload according to        PUSCH-Config-SDT-2 for the selected UL carrier and RSRP of the        downlink pathloss reference is greater than or equal to        sdt-Threshold-2        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-2.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        greater than TB size of payload according to PUSCH-Config-SDT-2        and (‘is greater than TB size of payload according to        PUSCH-Config-SDT-2 and’ can be removed in one embodiment) is        less than equal to the TB size of payload according to        PUSCH-Config-SDT-3 for SDT on UL carrier selected for        transmission and RSRP of the downlink pathloss reference is        greater than or equal to sdt-Threshold-3        -   UE initiate small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-2.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        greater than TB size of payload according to        PUSCH-Config-SDT-N−1 and (‘is greater than TB size of payload        according to PUSCH-Config-SDT-N−1 and’ can be removed in one        embodiment) is less than equal to the TB size of payload        according to PUSCH-Config-SDT-N for SDT on UL carrier selected        for transmission and RSRP of the downlink pathloss reference is        greater than or equal to sdt-Threshold-N

* UE initiate small data transmission using Preconfigured PUSCHresources in PUSCH-Config-SDT-N.  - Else: * UE does not initiate smalldata transmission using Preconfigured PUSCH resources. UE may initiatesmall data transmission using RACH if RACH based criteria to perform SDTis met.

Embodiment 2-2-3A—Option 3A

The gNB configures the parameter PUSCH-Config-SDT-1 andPUSCH-Config-SDT-2 in PUSCH configuration (for an UL carrier of campedcell) for SDT. The TBS is not explicitly signaled but determined basedon SCS, number of PRBs and number of OFDM symbols of PUSCH resource. TheTBS can also be explicitly signaled. sdt-Threshold-1 and sdt-Threshold-2are also configured. These parameters are separately configured for SULand NUL as UL coverage is different for SUL and NUL.

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH-Config-SDT-1        for SDT on UL carrier selected for transmission and RSRP of the        downlink pathloss reference is greater than or equal to        sdt-Threshold-1:        -   UE initiate small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-1.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        greater than TB size of payload according to PUSCH-Config-SDT-1        and (‘is greater than TB size of payload according to        PUSCH-Config-SDT-1 and’ can be removed in one embodiment) is        less than equal to the TB size of payload according to        PUSCH-Config-SDT-2 for the selected UL carrier and RSRP of the        downlink pathloss reference is greater than or equal to        sdt-Threshold-2

* UE initiate small data transmission using Preconfigured PUSCHresources in PUSCH-Config-SDT-2.  - Else * The UE does not initiatesmall data transmission using Preconfigured PUSCH resources. The UE mayinitiate small data transmission using RACH if RACH based criteria toperform SDT is met.

This option can be generalized wherein gNB configures the parametersPUSCH-Config-SDT-1 to PUSCH-Config-SDT-N; sdt-Threshold-1 tosdt-Threshold-N.

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH-Config-SDT-1        for SDT on UL carrier selected for transmission and RSRP of the        downlink pathloss reference is greater than or equal to        sdt-Threshold-1:        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-1.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        greater than TB size of payload according to PUSCH-Config-SDT-1        and (‘is greater than TB size of payload according to        PUSCH-Config-SDT-1 and’ can be removed in one embodiment) is        less than equal to the TB size of payload according to        PUSCH-Config-SDT-2 for the selected UL carrier and RSRP of the        downlink pathloss reference is greater than or equal to        sdt-Threshold-2        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-2.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        greater than TB size of payload according to        PUSCH-Config-SDT-N−1 and (‘is greater than TB size of payload        according to PUSCH-Config-SDT-N−1 and’ can be removed in one        embodiment) is less than equal to the TB size of payload        according to PUSCH-Config-SDT-N for SDT on UL carrier selected        for transmission and RSRP of the downlink pathloss reference is        greater than or equal to sdt-Threshold-N

* The UE initiates small data transmission using Preconfigured PUSCHresources in PUSCH-Config-SDT-N.  - Else: * UE does not initiate smalldata transmission using Preconfigured PUSCH resources. UE may initiatesmall data transmission using RACH if RACH based criteria to perform SDTis met.

Embodiment 2-2-4—Option 4: Multiple [TBS]

The gNB configures the parameter PUSCH-Config-SDT-1 andPUSCH-Config-SDT-2 in PUSCH configuration (for an UL carrier of campedcell) for SDT. The TBS is not explicitly signaled but determined basedon SCS, number of PRBs and number of OFDM symbols of PUSCH resource. TheTBSs can also be explicitly signaled. These parameters are separatelyconfigured for SUL and NUL as UL coverage is different for SUL and NUL.

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH-Config-SDT-1:        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-1.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        less than equal to the TB size payload according to        PUSCH-Config-SDT-2:

* The UE initiates small data transmission using Preconfigured PUSCHresources in PUSCH-Config-SDT-2.  - Else * The UE does not initiatesmall data transmission using Preconfigured PUSCH resources. The UE mayinitiate small data transmission using RACH if RACH based criteria toperform SDT is met.

This option can be generalized wherein gNB configures the parametersPUSCH-Config-SDT-1 and PUSCH-Config-SDT-N.

-   -   If the message size (UL data available for transmission plus MAC        header and, where required, MAC control elements) is less than        equal to the TB size of payload according to PUSCH-Config-SDT-1:        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-1.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        less than equal to the TB size of payload according to        PUSCH-Config-SDT-2:        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-2.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        less than equal to the TB size of payload according to        PUSCH-Config-SDT-3:        -   The UE initiates small data transmission using Preconfigured            PUSCH resources in PUSCH-Config-SDT-3.    -   Else if the message size (UL data available for transmission        plus MAC header and, where required, MAC control elements) is        less than equal to the TB size of payload according to        PUSCH-Config-SDT-N:

* The UE initiates small data transmission using Preconfigured PUSCHresources in PUSCH-Config-SDT-N.  - Else: * The UE does not initiatesmall data transmission using Preconfigured PUSCH resources. The UE mayinitiate small data transmission using RACH if RACH based criteria toperform SDT is met.

Embodiment 2-3—PDCCH Monitoring Upon Transmission Small Data inPreconfigured PUSCH Resource

Upon transmitting uplink data in preconfigured PUSCH resource, UE needsto monitor PDCCH for network response.

Search Space: The UE needs to know search space for monitoring PDCCH.One of the following options can be used for determining a search spacefor monitoring PDCCH for network response for SDT using preconfiguredPUSCH resource.

-   -   Option 1: sdt-SearchSpaceCG for SDT using preconfigured PUSCH        resource can be signaled by network in RRCRelease message along        with Preconfigured PUSCH resources.        -   1-1: sdt-SearchSpaceCG indicates one of the search space in            PDCCH-ConfigCommon IE of initial DL BWP or DL BWP with same            BWP ID as the UL BWP selected for SDT using preconfigured            PUSCH resource.        -   1-2: sdt-SearchSpaceCG indicates one of the search space in            PDCCH-Config IE of initial DL BWP or DL BWP with same BWP ID            as the UL BWP selected for SDT using preconfigured PUSCH            resource.    -   Option 2: sdt-SearchSpaceCG can be signaled by network in        initial DL BWP configuration (PDCCH-ConfigCommon IE or        PDCCH-Config IE) or DL BWP configuration with same BWP ID as the        UL BWP selected for SDT using preconfigured PUSCH resource.    -   sdt-SearchSpaceCG indicates the search space id of the search        space configuration (amongst the list of search space        configuration) to be used for PDCCH monitoring.    -   The UE monitors the search space using the RX beam corresponding        to SSB associated with UL grant in which transmission is made by        UE.

RNTI: The UE needs to know the RNTI for monitoring PDCCH. UE can monitorPDCCH addressed to C-RNTI where the C-RNTI is the one which the UE usedin cell from which it received preconfigured PUSCH resources.Alternately, the C-RNTI can be assigned along with preconfigured PUSCHresources (e.g. in RRCRelease message).

Monitoring Time: The UE needs to know the time interval for monitoringresponse. A timer can be configured by network along with preconfiguredPUSCH resources. The timer can be started from end of PUSCH transmissionor at the first PDCCH monitoring occasion from the end of PUSCHtransmission or at a fixed offset from the end of PUSCH transmission. Ifthe UE receives PDCCH addressed to C-RNTI and TB is successfullydecoded, the timer is stopped.

Retransmission Handling:

-   -   Option 1: No retransmissions. If the timer expires, SDT is        considered to have failed.    -   Option 2: Timer based retransmissions: The UE retransmits the        generated MAC PDU using preconfigured PUSCH resource if it has        not yet transmitted the MAC PDU configurable number of times. If        UE has transmitted the MAC PDU the configurable number of times,        SDT is considered to have failed.        -   During retransmission, the UE first selects SSB (in an            embodiment, UE uses the same SSB as was selected during the            first transmission); UE then selects PUSCH resource            corresponding to the selected SSB; the UE then transmits in            selected PUSCH resource; the UE starts the monitoring timer            and waits for response (i.e., PDCCH addressed to C-RNTI). If            UCI is supported, the UE may indicate new            transmission/retransmission in the UCI. Redundancy Version            (RV) may be pre-defined for each            transmission/retransmission.        -   During retransmission, power ramping may be performed for            PUSCH transmission. The power of the previous transmission            may be ramped by a power ramping step. The power ramping            step is signaled by the gNB.    -   Option 3: Network triggered retransmissions:        -   The UE performs HARQ retransmission if the UE receives PDCCH            addressed to C-RNTI for HARQ retransmission of HARQ process            used for SDT using preconfigured PUSCH resource. PDCCH            indicates UL grant for retransmission. HARQ process used for            SDT using preconfigured PUSCH resource can be signaled in            SDT configuration or can be pre-defined.        -   The UE re-starts the monitoring timer and waits for            response.        -   The UE continues to use the SSB selected during initial            transmission.        -   During retransmission, power ramping can be performed for            PUSCH transmission. The power of the previous transmission            may be ramped by a power ramping step. The power ramping            step is signaled by gNB.

In the response to the small data transmission, UE may receive a signal(RRC message or DCI) for the following purpose:

releasing pre-configured PUSCH or switching to Resume procedure (i.e.RRC_CONNECTED).

Embodiment 2-4—Release of Preconfigured PUSCH Resource

Option 1: Timer based Release

-   -   Timer is (re-) started upon receiving preconfigured PUSCH        resource in release message. Upon expiration of the timer,        preconfigured PUSCH resources are released.

Option 2: Release upon number of occurrences

-   -   The MAC entity shall discard the immediately Preconfigured PUSCH        resource after ‘N’ number of consecutive association periods in        which grant was not used. Association period is equal to        periodicity of configured grant*X where X is number of SSBs        associated with configured grant.

Option 3: Reception of RRCRelease without any Preconfigured PUSCHresource or any indication to use the previously configured resources

Option 4: Release upon cell change

Option 5: Release upon connection resume

Option 6: gNB may want to release the pre-configured PUSCH for InactiveUE. Then RAN paging can be used. New field in RAN paging can beintroduced. If UE receives RAN paging with the new field, UE releasespre-configured PUSCH, but need not switch to RRC_CONNECTED.

Embodiment 2-5—Signaling Flow without Context Fetch

FIG. 4 illustrates a flow chart for small data transmission usingpreconfigured uplink resource according to an embodiment of thedisclosure.

Referring to FIG. 4, in this case it is assumed the gNB has the UE'scontext.

0. Criteria to initiate SDT using preconfigured PUSCH resources is met.

1. In the preconfigured PUSCH resource, the UE sends anRRCResumeRequest/RRCResumeRequest1 to the gNB (same as the last servingGNB) on SRB 0 in operation 410. The request includes full/short I-RNTI(resumeIdentity), the resume cause (resumeCause), and an authenticationtoken (resumeMAC-I). The I-RNTI (short or full I-RNTI) is used forcontext identification and its value shall be the same as the I-RNTIthat the UE had received from the last serving gNB in the RRCReleasewith suspendConfig message. The ResumeMAC-I is a 16-bit messageauthentication token, the UE shall calculate it using the integrityalgorithm (NIA or EIA) in the stored AS security context, which wasnegotiated between the UE and the last serving gNB and the KRRCint fromthe stored AS security context with the following inputs:

-   -   KEY: shall be set to current KRRCint;    -   BEARER: all bits shall be set to 1.    -   DIRECTION: shall be set to 1;    -   COUNT: all bits shall be set to 1;    -   MESSAGE: shall be set to VarResumeMAC-Input with following        inputs:        -   source PCI (set to the physical cell identity of the PCell            the UE was connected to prior to suspension of the RRC            connection)        -   target Cell-ID (set to the cellIdentity of the first            PLMN-Identity included in the PLMN-IdentityInfoList            broadcasted in SIB1 of the target cell i.e. the cell to            which the UE is sending small data)        -   source C-RNTI (set to C-RNTI that the UE had in the PCell it            was connected to prior to suspension of the RRC connection).

The UE resumes all SRBs and DRBs, derives new security keys using theNextHopChainingCount provided in the RRCRelease message of the previousRRC connection, and re-establishes the AS security. The user data areciphered and integrity protected (only for DRBs configured with UPintegrity protection) and transmitted on DTCH multiplexed with theRRCResumeRequest/RRCResumeRequest1 message on CCCH.

Alternately, the UE can transmit small data by using one of thefollowing options:

-   -   RRCResumeRequest (or new RRC message). resumeIdentity,        ResumeMAC-I, resumeCause, NAS container in        RRCResumeRequest/RRCResumeRequest1. NAS container includes UL        data.    -   new MAC CE (resumeIdentity, ResumeMAC-I)+uplink data (on DTCH).        resumeIdentity is provided for UE identification purpose.        ResumeMAC-I is for security.

2. The gNB validates the resumeMAC-I and delivers the uplink data to theUPF in operation 420.

3. The gNB sends the RRCRelease message to keep the UE in RRC_INACTIVE.The PDCCH is addressed to C-RNTI. The C-RNTI is the one which the UEused in cell from which it received preconfigured PUSCH resources.Alternately, the C-RNTI can be assigned along with preconfigured PUSCHresources. If downlink data is available in operation 430, the downlinkdata are sent ciphered and integrity protected (only for DRBs configuredwith UP integrity protection) on DTCH multiplexed with the RRCReleasemessage on DCCH in operation 440.

(Alternate 1) Consider an alternate signaling flow wherein gNB canschedule UL grant (PDCCH addressed to C-RNTI) before RRCRelease. In theUL transmission, the UE can indicate if the UE has more data totransmit. If the UE has more data to transmit, the gNB can schedule ULgrant. Otherwise RRCRelease. In the UL transmission, the UE can alsoinclude SSB ID(s) of SSB above threshold if the SSB indicated by PRACHpreamble is no longer suitable.

(Alternate 2) Alternately, the gNB can transmit PDCCH addressed to RNTI(i.e. RNTI is the one assigned by gNB along with preconfigured resource,the RNTI can be assigned to other UEs as well) and scheduled DL TBincludes contention resolution identity (it is first X bits (e.g. 48bits) of resume message) and C-RNTI. If it matches with UE's contentionresolution identity, UE stops the monitoring timer and UE can considersmall data transmission as successful.

In the response of the small data transmission, UE can receive a signal(RRC message or DCI) for the following purpose:

releasing pre-configured PUSCH or switching to Resume procedure (i.e.RRC_CONNECTED).

Embodiment 2-6—an Example Signaling Flow with Context Fetch and PathSwitching

FIG. 5 illustrates a flow chart for small data transmission usingpreconfigured uplink resource according to embodiment of the disclosure.

Referring to FIG. 5, in this case it is assumed the gNB does not havethe UE's context and fetches the same from last serving gNB. Path switchis performed and context is released from last serving gNB. This canoccur only when the UE is transmitting using pre-configured PUSCHresource in a cell other than the cell from which UE has last receivedRRC release message.

0. Criteria to initiate SDT using preconfigured PUSCH resources is met.

1. In the preconfigured PUSCH resource, UE sends anRRCResumeRequest/RRCResumeRequest1 to the gNB (different from lastserving gNB) on SRB 0 in operation 510. The request includes full/shortI-RNTI (resumeIdentity), the resume cause (resumeCause), and anauthentication token (resumeMAC-I). The I-RNTI (short or full I-RNTI) isused for context identification and its value shall be the same as theI-RNTI that the UE had received from the last serving gNB in theRRCRelease with suspendConfig message. The ResumeMAC-I is a 16-bitmessage authentication token. The UE shall calculate the ResumeMAC-Iusing the integrity algorithm (NIA or EIA) in the stored AS securitycontext, which was negotiated between the UE and the last serving gNBand the KRRCint from the stored AS security context with the followinginputs:

-   -   KEY: shall be set to current KRRCint;    -   BEARER: all bits shall be set to 1.    -   DIRECTION: shall be set to 1;    -   COUNT: all bits shall be set to 1;    -   MESSAGE: shall be set to VarResumeMAC-Input with following        inputs:        -   source PCI (set to the physical cell identity of the PCell            the UE was connected to prior to suspension of the RRC            connection).        -   target Cell-ID (Set to the cellIdentity of the first            PLMN-Identity included in the PLMN-IdentityInfoList            broadcasted in SIB1 of the target cell i.e. the cell the UE            is trying to resume).        -   source C-RNTI (Set to C-RNTI that the UE had in the PCell it            was connected to prior to suspension of the RRC connection).

The UE resumes all SRBs and DRBs, derives new security keys using theNextHopChainingCount provided in the RRCConnectionRelease message of theprevious RRC connection, and re-establishes the AS security. The userdata are ciphered and integrity protected (Only for DRBs configured withUP integrity protection) and transmitted on DTCH multiplexed with theRRCResumeRequest/RRCResumeRequest1 message on CCCH.

2. The gNB (i.e., target GNB) identifies the GNB identity of lastserving gNB (i.e., source gNB) from I-RNTI and requests the last servinggNB to provide the UE's context data by sending an Retrieve UE ContextRequest message with the following included: I-RNTI, the ResumeMAC-I andtarget Cell-ID, in order to allow the source gNB to validate the UErequest and to retrieve the UE context in operation 515.

3. The last serving gNB (i.e., source gNB) validates the resumeMAC-I andprovides the UE context data.

The source gNB retrieves the stored UE context including the UE 5G ASsecurity context from a database using the I-RNTI. The source gNBverifies the ResumeMAC-I using the current K_(RRCint) key stored in theretrieved UE 5G AS security context (calculating the ResumeMAC-I in thesame way as described above). If the verification of the ResumeMAC-I issuccessful, then the source gNB calculates K_(NG-RAN)* using the targetcell PCI, target ARFCN-DL and the KgNB/NH in the current UE 5G ASsecurity context based on either a horizontal key derivation or avertical key derivation according to whether the source gNB has anunused pair of {NCC, NH}. The source gNB can obtain the target PCI andtarget ARFCN-DL from a cell configuration database by means of thetarget Cell-ID which was received from the target gNB. Then the sourcegNB shall respond with an Xn-AP Retrieve UE Context Response message tothe target gNB including the UE context that contains the UE 5G ASsecurity context in operation 520. The UE 5G AS security context sent tothe target gNB shall include the newly derived K_(NG-RAN)*, the NCCassociated to the K_(NG-RAN)*, the UE 5G security capabilities, UPsecurity policy, the UP security activation status with thecorresponding PDU session ID(s), and the ciphering and integrityalgorithms used by the UE with the source cell.

4. If loss of DL user data buffered in the last serving gNB shall beprevented, the gNB provides forwarding addresses in operation 525.

5. The gNB performs path switch in operations 530 and 535.

6. The gNB triggers the release of the UE resources at the last servinggNB in operation 540.

7. The gNB delivers the uplink data to UPF in operation 545.

8. The gNB sends the RRCRelease message to keep the UE in RRC_INACTIVE.The PDCCH is addressed to C-RNTI. The C-RNTI is the one which the UEused in cell from which it received preconfigured PUSCH resources.Alternately, the C-RNTI can be assigned along with preconfigured PUSCHresources. If downlink data is available in operation 550, the downlinkdata are sent ciphered and integrity protected (only for DRBs configuredwith UP integrity protection) on DTCH multiplexed with the RRCReleasemessage on DCCH in operation 555.

(Alternate 1) We can consider an alternate signaling flow wherein gNBcan schedule UL grant (PDCCH addressed to C-RNTI) before RRCRelease. Inthe UL transmission UE can indicate if it has more data to transmit. IfUE has more data to transmit, gNB can schedule UL grant. OtherwiseRRCRelease. In the UL transmission, UE can also include SSB ID(s) of SSBabove threshold if the SSB indicated by PRACH preamble is no longersuitable.

(Alternate 2) Alternately gNB can transmit PDCCH addressed to RNTI (i.e.RNTI is the one assigned by gNB along with preconfigured resource, itcan be assigned to other UEs as well) and scheduled DL TB includescontention resolution identity (it is first X bits (e.g. 48 bits) ofresume message) and C-RNTI. If it matches with UE's contentionresolution identity, UE stops the monitoring timer and UE can considersmall data transmission as successful.

In the response of the small data transmission, UE can receive a signal(RRC message or DCI) for the following purpose:

releasing pre-configured PUSCH or switching to Resume procedure (i.e.RRC_CONNECTED).

Embodiment 2-7—MAC PDU Generation for SDT

In one method of this disclosure, for small data transmission inRRC_INACTIVE using MsgA or Msg3 or preconfigured PUSCH resource, none ofthe LCH restrictions are applied while generating MAC PDU.

FIG. 6 illustrates a flow chart for generating medium access control(MAC) protocol data unit (PDU) for small data transmission according toan embodiment of the disclosure.

Referring to FIG. 6, if UL grant is available for new transmission atoperation 610, whether this UL grant is for SDT is determined atoperation 620. If the UL grant is for SDT, the UE selects all logicalchannels (i.e., logical channels corresponding to RBs which are resumedupon initiating small data transmission procedure) for MAC PDUgeneration at operation 640, and applies LCP procedure for the selectedlogical channels at operation 650. Otherwise, the UE selects the logicalchannels (among the logical channels corresponding to RBs which areresumed upon initiating small data transmission procedure) which areallowed to be transmitted in this UL grant according to at least one ofallowedSCS-List, maxPUSCH-Duration, configuredGrantType1Allowed,allowedServingCells, allowedCG-List or allowedPHY-PriorityIndex for MACPDU generation at operation 630.

FIG. 7 illustrates a flow chart for generating MAC PDU for small datatransmission according to an embodiment of the disclosure.

Referring to FIG. 7, allowedSCS-List and maxPUSCH-Duration are appliedfor generating MAC PDU for SDT. This means that if LCH is configuredwith allowedSCS-List and SCS included in allowedSCS-List is not the SCSof UL grant used for SDT, this LCH is not selected for SDT. This meansthat if LCH is configured with maxPUSCH-Duration and duration includedin allowedSCS-List is not the duration of UL grant used for SDT, thisLCH is not selected for SDT. AllowedServingCells is not applied forgenerating MAC PDU for SDT. ConfiguredGrantType1Allowed is not appliedfor RACH based small data transmission but allowed for non RACH basedsmall data transmission. For non RACH based small data transmission, ifLCH is not configured with configuredGrantType1Allowed, this LCH is notselected for SDT.

Specifically, if UL grant is available for new transmission at operation710, whether this UL grant is for SDT is determined at operation 720. Ifthe UL grant is not for SDT, the UE selects the logical channels whichare allowed to be transmitted in this UL grant according toallowedSCS-List, maxPUSCH-Duration, configuredGrantType1Allowed,allowedServingCells, allowedCG-List and allowedPHY-PriorityIndex for MACPDU generation at operation 730. Otherwise, the UE determines whetherthe UL grant is a pre-configured UL grant or not at operation 740. Ifthe UL grant is a pre-configured UL grant, the UE selects the logicalchannels (amongst the logical channels corresponding to RBs which areresumed upon initiating small data transmission procedure) which areallowed to be transmitted in this UL grant according to allowedSCS-List,maxPUSCH-Duration, configuredGrantType1Allowed at operation 770, andapplies LCP procedure for the selected logical channels at operation760. If the UL grant is not a pre-configured UL grant, the UE selectsthe logical channels (amongst the logical channels corresponding to RBswhich are resumed upon initiating small data transmission procedure)which are allowed to be transmitted in this UL grant according toallowedSCS-List, maxPUSCH-Duration at operation 750, and applies LCPprocedure for the selected logical channels at operation 760.

In one method of this disclosure, the network indicates whether to applyLCH restrictions or not. Indication can be in RRCRelease or RACHconfiguration for SDT. If network indicates to apply LCH restrictions,all LCH restrictions are considered while selecting LCH for SDT. In anembodiment, restrictions that can be applied may also be indicated fromthe network. In this case, UE only applies the indicated LCHrestrictions while selecting LCH for SDT.

FIG. 8 is a block diagram of a terminal according to an embodiment ofthe disclosure.

Referring to FIG. 8, a terminal includes a transceiver 810, a controller820 and a memory 830. The controller 820 may refer to a circuitry, anapplication-specific integrated circuit (ASIC), or at least oneprocessor. The transceiver 810, the controller 820 and the memory 830are configured to perform the operations of the terminal illustrated inthe FIGS. 1 to 7, or described above. Although the transceiver 810, thecontroller 820 and the memory 830 are shown as separate entities, theymay be realized as a single entity like a single chip. Or, thetransceiver 810, the controller 820 and the memory 830 may beelectrically connected to or coupled with each other.

The transceiver 810 may transmit and receive signals to and from othernetwork entities, e.g., a base station.

The controller 820 may control the terminal to perform functionsaccording to one of the embodiments described above. For example, thecontroller 820 controls the transceiver 810 and/or memory 830 to performsmall data transmission and reception according to various embodimentsof the disclosure.

In an embodiment, the operations of the terminal may be implementedusing the memory 830 storing corresponding program codes. The terminalmay be equipped with the memory 830 to store program codes implementingdesired operations. To perform the desired operations, the controller820 may read and execute the program codes stored in the memory 830 byusing at least one processor or a CPU.

FIG. 9 is a block diagram of a base station according to an embodimentof the disclosure.

Referring to FIG. 9, a base station includes a transceiver 910, acontroller 920 and a memory 930. The controller 920 may refer tocircuitry, an ASIC, or at least one processor. The transceiver 910, thecontroller 920 and the memory 930 are configured to perform theoperations of the UE illustrated in FIGS. 1 to 7, or as described above.Although the transceiver 910, the controller 920 and the memory 930 areshown as separate entities, they may be realized as a single entity likea single chip. The transceiver 910, the controller 920 and the memory930 may be electrically connected to or coupled with each other.

The transceiver 910 may transmit and receive signals to and from othernetwork entities, e.g., a terminal.

The controller 920 may control the base station to perform functionsaccording to one of the embodiments described above. For example, thecontroller 920 controls the transceiver 910 and/or memory 930 to performsmall data transmission and reception according to various embodimentsof the disclosure.

In an embodiment, the operations of the base station may be implementedusing the memory 930 storing corresponding program codes. The basestation may be equipped with the memory 930 to store program codesimplementing desired operations. To perform the desired operations, thecontroller 920 may read and execute the program codes stored in thememory 930 by using at least one processor or a CPU.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

What is claimed is:
 1. A method performed by a terminal in a wirelesscommunication system, the method comprising: receiving, from a basestation, a radio resource control (RRC) release message including atleast one configured grant uplink resource for a small data transmission(SDT); identifying an uplink carrier among a normal uplink (NUL) or asupplementary uplink (SUL), based on an SDT procedure initiated whilethe terminal is in an RRC inactive state; identifying a synchronizationsignal block (SSB) among SSBs associated with configured grant uplinkresources for the SDT procedure on the identified uplink carrier; andtransmitting, to the base station, an uplink data in an uplink grantcorresponding to the identified SSB.
 2. The method of claim 1, whereinthe at least one configured grant uplink resource for the SDT includes afirst configured grant uplink resource for the NUL and a secondconfigured grant uplink resource for the SUL.
 3. The method of claim 1,wherein the RRC release message further includes information on an SDTsearch space for monitoring a physical downlink control channel (PDCCH)for a response to the uplink data and information on a cell radionetwork temporary identifier (C-RNTI) for monitoring the PDCCH, andwherein the information on the SDT search space indicates one from atleast one search space configured for a downlink bandwidth part.
 4. Themethod of claim 1, wherein the uplink carrier is identified based on afirst reference signal received power (RSRP) threshold associated withSUL for the SDT, and wherein the first RSRP threshold associated withSUL for the SDT is configured from the base station.
 5. The method ofclaim 1, wherein the SSB is identified based on a second referencesignal received power (RSRP) threshold associated with SSB for the SDT,and wherein the second RSRP threshold associated with SSB for the SDT isconfigured from the base station.
 6. A method performed by a basestation in a wireless communication system, the method comprising:transmitting, to a terminal, a radio resource control (RRC) releasemessage including at least one configured grant uplink resource for asmall data transmission (SDT); and receiving, from the terminal, anuplink data in an uplink grant corresponding to a synchronization signalblock (SSB), based on an SDT procedure initiated while the terminal isin an RRC inactive state, wherein the SSB is one among SSBs associatedwith configured grant uplink resources for the SDT procedure on anuplink carrier, and wherein the uplink carrier is one among a normaluplink (NUL) or a supplementary uplink (SUL).
 7. The method of claim 6,wherein the at least one configured grant uplink resource for the SDTincludes a first configured grant uplink resource for the NUL and asecond configured grant uplink resource for the SUL.
 8. The method ofclaim 6, wherein the RRC release message further includes information onan SDT search space for monitoring a physical downlink control channel(PDCCH) for a response of the uplink data and information on a cellradio network temporary identifier (C-RNTI) for monitoring the PDCCH,and wherein the information on the SDT search space indicates one fromat least one search space configured for a downlink bandwidth part. 9.The method of claim 6, wherein information on a first reference signalreceived power (RSRP) associated with SUL for the SDT is transmitted tothe terminal for identifying the uplink carrier.
 10. The method of claim6, wherein information on a second reference signal received power(RSRP) associated with SSB for the SDT is transmitted to the terminalfor identifying the SSB.
 11. A terminal in a wireless communicationsystem, the terminal comprising: a transceiver; and a controllerconfigured to: receive, from a base station via the transceiver, a radioresource control (RRC) release message including at least one configuredgrant uplink resource for a small data transmission (SDT), identify anuplink carrier among a normal uplink (NUL) or a supplementary uplink(SUL), based on an SDT procedure initiated while the terminal is in anRRC inactive state, identify a synchronization signal block (SSB) amongSSBs associated with configured grant uplink resources for the SDTprocedure on the identified uplink carrier, and transmit, to the basestation via the transceiver, an uplink data in an uplink grantcorresponding to the identified SSB.
 12. The terminal of claim 11,wherein the at least one configured grant uplink resource for the SDTincludes a first configured grant uplink resource for the NUL and asecond configured grant uplink resource for the SUL.
 13. The terminal ofclaim 11, wherein the RRC release message further includes informationon an SDT search space for monitoring a physical downlink controlchannel (PDCCH) for a response of the uplink data and information on acell radio network temporary identifier (C-RNTI) for monitoring thePDCCH, and wherein the information on the SDT search space indicates onefrom at least one search space configured for a downlink bandwidth part.14. The terminal of claim 11, wherein the uplink carrier is identifiedbased on a first reference signal received power (RSRP) thresholdassociated with SUL for the SDT, and the first RSRP threshold associatedwith SUL for the SDT is configured from the base station.
 15. Theterminal of claim 11, wherein the SSB is identified based on a secondreference signal received power (RSRP) threshold associated with SSB forthe SDT, and wherein the second RSRP threshold associated with SSB forthe SDT is configured from the base station.
 16. A base station in awireless communication system, the base station comprising: atransceiver; and a controller configured to: transmit, to a terminal viathe transceiver, a radio resource control (RRC) release messageincluding at least one configured grant uplink resource for a small datatransmission (SDT), and receive, from the terminal via the transceiver,an uplink data in an uplink grant corresponding to a synchronizationsignal block (SSB), based on an SDT procedure initiated while theterminal is in an RRC inactive state, wherein the SSB is one among SSBsassociated with configured grant uplink resources for the SDT procedureon an uplink carrier, and wherein the uplink carrier is one among anormal uplink (NUL) or a supplementary uplink (SUL).
 17. The basestation of claim 16, wherein the at least one configured grant uplinkresource for the SDT includes a first configured grant uplink resourcefor the NUL and a second configured grant uplink resource for the SUL.18. The base station of claim 16, wherein the RRC release messagefurther includes information on an SDT search space for monitoring aphysical downlink control channel (PDCCH) for a response of the uplinkdata and information on a cell radio network temporary identifier(C-RNTI) for monitoring the PDCCH, and wherein the information on theSDT search space indicates one from at least one search space configuredfor a downlink bandwidth part.
 19. The base station of claim 16, whereininformation on a first reference signal received power (RSRP) associatedwith SUL for the SDT is transmitted to the terminal for identifying theuplink carrier.
 20. The base station of claim 16, wherein information ona second reference signal received power (RSRP) associated with SSB forthe SDT is transmitted to the terminal for identifying the SSB.